Compounded oil



Patenteoi in. H3, 1942 v STATE comroummn on. v

James o. (Jlayton and Bruce B. Farrington, Berkeley, Oalii'., assignors to Standard Oil Company of California, San Francisco, Calif., a corporation of Delaware No Drawing. Application June 10, 1940, Serial No. 339,660

24 Claims.

This invention relates to a new and useful composition of matter comprising a compounded hy-- drocarbon oil. More particularly. it involves the provision of a lubricating oil containing metal salts of organic acids and an addition agent which inhibits undesirable effects of such compounds, as set forth hereinafter.

Metal salts of organic'acids are known as compounding ingredients for lubricating oils and have been added thereto for various purposes. For example, aluminum oleate is disclosed as a dispersing agent for graphite in the United States patent to Burke No. 1,732,221, various soaps have been disclosed as pour point depressing agents, and the patent to Parker No. 2,001,108 is directed to metal naphthenates as stabilizing agents for lubricating oils. In its broader aspects this invention is applicable to compounded oils containing metal salts of organic acids of the above known types, as well as to oils containing novel types of salts hereinafter disclosed. The present invention, in its more specific aspects, is concerned with oils compounded with-certain metal salts among which are poLvvalent metal salts, such as salts of alumin zinc, tin, magnesium, calcium and chror'nium.

One important property of lubricating oils is low corrosivity, especially with respect to modern bearing metals such as copper-lead or cadmiumsilver alloys. Some lubricating oils which have been entirely satisfactory from the standpoint of corrosivity to high grade Babbitt bearing metals show a corrosion rate which is greater than is desirable with bearing metals of a type represented by cadmium-silver and copper-lead bearings.

Lubricating oils containing metal salt compound ing ingredients have been found, in general, to show undesirable corrosive eiiects on such bearing materials. However, these metal salt compounding ingredients are highly desirable or even necessary for other purposes, such as for inhibiting piston ring sticking in internal combustion engines such as Diesel engines.

organic acids by incorporating therein an ester containing an amino group preferably no more than two carbon atoms removed from a carbonyl group of said ester.

Additional objects and advantages of the invention will become apparent from the disclosure which follows.

Examples of metal salts of organic acids which may be incorporated in lubricating oils accordin to the principles of this invention are metal salts of higher fatty or aliphatic acids, metal salts of naphthenic acids, metal salts of oil-soluble substituted phenols, and metal salts of carboxylic acids containing an aryl substituent.

Among the metal salts of higher fatty acids may be mentioned: aluminum laurate, aluminum oleate, aluminum stearate, aluminum ricinoleate; zinc laurate, zinc oleate, zinc stearate, zinc ricinoleate; tin laurate, tin oleate, tin stearate, tin ricinoleate; magnesium laurate, magnesium oleate, magnesium stearate, magnesium ricinoleate; calcium laurate, calcium oleate, calcium stearate, calcium ricinoleate; chromium laurate, chromium oleate, chromium stearate, and chromium ricinoleate.

Examples of metal naphthenates are: aluminum'naphthenate, zinc naphthenate, magnesium napthenate, cobalt naphthenate, cadmium naphthenate, tin naphthenate and manganese naphthenate. The naphthenic acid component of these salts may conveniently be obtained, from petroleum.

Metal phenates which may be mentioned comprise metal salts of a substituted phenol oi the type formula:

ll I

- in which u, v, 10, s and y are selected from the Accordingly, it is an object of the invention to I solve the above diflicultles by providing an improved compounded mineral oi l containing metal salts of organic acids.

Another object of the invention is to inhibit corrosive effects of compounded lubricating oils containing metal salts of organic acids.

A further object of the invention is to increase the stability of lubricating oils with respect to oxidation or discoloration or gum-iormation.-

A still further object is to improve the properties of lubricating oils containing metalsalts of group consisting of hydrogen, alkyl, aryl, alkaryl, aralkyl and cyclic non-benzenoid hydrocarbon radicals. Specific illustrations of such phenates are the aluminum,zinc, tin, magnesium, calcium and chromium as well as other polyvalent metal salts of cetyl phenol. The phenolic radical of the salts preferably contains more than about ten carbon atoms and also should preferably have an alkyl substituent substituted in the benzene ring to which the hydroxyl group of the phenol is directly attached. P Examples of carboxylic acids containing an aryl substituent are: phenyl stearic acid, naphthyl stearic acid, 'phenyl lauric acid, alpha loenzal stearic acid, alpha henzal lauric acid, and analosous homologues of these acids formed by condensation or an aromatic aldehyde with a fatty acid according to the reaction:

I (@HR: where R1 is an alkyl and R2 an aryl radical. Aluminum, zinc, tin, magnesium, calcium and chromium as well as other polyvalent metal salts of each of the above acids may be utilized.

The invention also includes salts of polycarboxylic acids together with amino esters in hydrocaroon oils. Examples of such salts are the aluminum, zinc, tin, magnesium, calcium and chromium as well as other polyvalent metal salts of partially esteriiied acids of the oxalic acid series, including oxalic acid itself, malonic acid, isosuccinic or methyl malonic acid and its alkyl homoloaues, as Well as the corresponding salts of partially esterifled alkyl tartronic acid, partially esterifled malic acid and its homologues, partially esterified oxyglutaric acid, partially es- 'terified hydroxy adipic acid, partially esterified tartaric acid, partially esterifled citric acid and the like.

The second component of the composition of this invention comprises oil-soluble esters containing an amino group preferably no more than two carbon atoms removed from a carbonyl group of the esters. These types'oi compounds may be represented generically hy the following structural formulae:

Alpha amino ester In these formulae R1 and R2 represent an alkyl, aryl, alkaryl, varallryl or cyclic non-henzenoid group. R1 and R2 may contain substituents other than the amino group, which substituents may be of either the same or a diherent type. X represents an amino group which may be any one of the following:

radicals are phenyl and naphthyl. Examples of alkaryl radicals are radicals in which a benzene ring is attached directly to the molecule being substituted, and the benzene ring contains an alkyl suh-stituent. Examples of arallsyl radicals are radicals in which an alkyl group is attached directly to the molecule being substituted, and the allryl group contains an aryl substituent, for

act/ 1 is instance, an ester of phenyl methyl alcohol. Examples of cyclic non-benzenoid radicals are cyclo pentyl, cyclo hexyl and cyclo heptyl.

Examples of alpha amino esters are esters of glycine, alanine, amino-malomc acid, aspartic acid and dimethylamino-acetic acid, such as the following: ethyl glycocollate, amyl glycocollate, octyl glycocollate, decyl glycocollate, lauryl glycocollate, tetradecyl glycocollate, cetyl glycocollate; octyl alpha amino-propionate, decyl alpha amino propionate, lauryl alpha amino-propionate, tetradecyl alpha amino-propionate, cetyl alpha amino-propionate; diethyl amino-melonate, dioctyl amino-malonate, didecyl amino-"nalonate, dilauryl amino-malonate, ditetradecyl amino-malonate, dicetyl amino-malonate; diethyl aspartate, dioctyl aspartate, didecyl aspartate, dilauryl aspartate, dietetradecyl aspartate,

dicetyl aspartate; octyl dimethylamino-acetic acid, decyl dimethylamino-acetic acid, lauryl dimethylamino-acetic acid tetradecyl dimethylamino-acetic acid, and cetyl dimethylaminoacetic acid.

Examples of beta amino esters comprise esters of beta alanine, beta dimethylamino-propionic acid, beta amino loutyric acid, and beta. amino isovaleric acid, such as the following: beta amino propionic octyl ester, beta amino propionic decyl ester, beta amino propionic lauryl ester, beta amino propionic tetradecyl ester, heta amino propionic cetyl ester; beta dimethylamino-propionic octyl ester, beta dimethylarnino-propionie decyl ester, beta dimethylamino-propionic lauryl ester, beta dimethylamino-propionic tetradecyl ester, beta dimethylarohoo propionic cetyl ester; beta amino butyrlc octyl ester, heta amino butyric deoyl ester, heta amino hutyric lauryl ester, heta amino hutyrictetradecyl ester, beta amino butyric cetyl ester; beta amino isovaleric octyl ester, beta amino isoyaleric decyl ester, beta amino isovaleric lauryl ester, beta amino isovalerlc tetradecyl ester, and hats, amino lsovaleric cetyl ester.

The amino esters of this invention may he prepared loy rneth'ods known in the art. 'The esters he produced by esterlfication of the alpha or beta amino acids, by esteriflcation of alpha or beta amlno'alcohols, or by introducing an amino eroup into an ester ln'an alpha or beta position. For example, either ethyl or amyl amino acetate may he prepared by passing dry HCI gas through a suspension of glycin hydrochloride in the corresponding alcohol, crystallizing the hydrochloride or the ester from the alcohol, decomposing the hydrochloride in a cold solution of sodium hydroxide and extracting the reaction product several times with ether. The ether solution is then agitated for several hours with potassium carhonate and then with calcium oxide, after which the ether is evaporated oil and the residue fractionated. Other amino esters, including diethyl aspartate and diethyl amino-malo'nate may he orehared by similar methods.

It is nreferred that the amino, esters be of the non-polymerizahletype since polymerized esters having molecular Weights over 800 increase the viscosity of the oil, which is not desired in many instances.

it will he understood from the foregoing discussion that the invention embraces the addition of both a metal salt of an organic acid and an amino ester. as addition agents for liquid lubriforegoing amino substituted esters to impart improved properties to the oil: e. g.. lubricating oils containing any one .or more of the metal salts'of fatty acids with any one or more of the alpha or beta amino esters will be found useful. Likewise,

oils containing any one or. more of'the metal naphthenates in combination with any one or countered and the type of bearings or other machine elements to be lubricated, if-the maximum .beneflts of the invention are to lie obtained. In

In general, the alpha or beta amino esters reduce I the corrosive effects of hydrocarbon lubricating oils on modern bearing metals, such as copperlead or cadmium-silver alloys. reduce corrosiveness of oils containing metal salts of organic acids as much as 50% or more. Various of the metal salts of organic acids and amino esters apparently cooperate to enhance the stability of the oil against discoloration, gum formation, piston ring sticking and the like.

' Examples of specific combinations and proportions in lubricating oils are as follows: 1% of aluminum oleate with 1% of amyl glycocollate in an S. A. E. 30 acid refined naphthenic base lubricating oil; 1% of aluminum naphthenate with 1% of amyl glycocollate in the same type oil; 0.5% of calcium cetyl phenate with 0.25%

amyl glycocollate in the same type oil; 1% of calcium lauryl phenate with 0.25% amyl glycocollate; 1% of calcium phenyl stearate with 0.25% amyl glycoco1late;and 1% of a calcium salt of alpha benzal stearic acid with 1% amyl glycocollate-all in the same type oil.

The proportions of addition agents utilized will depend upon the particular compounds incorpo- Such esters will rated in the oil, upon the base oil being compounded, as well as upon the conditions which the oil is to encounter during use and the properties desired. In general, from 0.1% to 5% of the metal salts 'of organic acids are utilized, and more usually 0.5% to 2% thereof are found desirable.

. Measurable improvements in the properties of as highly refined or highly parai iinic mineral oils,

.which are inthemselves corrosive to bearing metals in the absence of added metal salts of organic acids; re..- the alpha or beta amino esters may, according to the broader principles of the invention, be utilized to inhibit the corrosive action of hydrocarbon lubricating oils on copperlead and cadmium-silver bearing metals whether or not the oils contain metal salts, However, the invention appears to find its greatest utility in oils containing metal salts of organic acids in that'these salts cooperate with the esters in yield properties which are not obtainable with either type of component alone. 7

It is apparent that the particular ester and the particular metal salt must be selected with various factors in mind, such as the service to be engeneral, salts containing at least ten carbon atoms are preferred. Where reduced corrosion is desired esters containing less than ten carbon atoms are preferred. Esters containing more than ten carbon atoms are useful in imparting other properties to the oil, e. g., reducing wear and reducing frictiom Whilaspecific examples and methods of preparation of the compositions of the invention have been described, this has been done by way of illustration only and with the intention that no limitation should be imposed upon the invention thereby. Numerous modifications and variations of the illustrative examples may be effected in the practice of the invention which is of the scope of the claims appended hereto.

We claim:

1. A liquid compounded hydrocarbon oil containing a metal salt of an organic acid in an amount suflicient substantially to increase the corrosivity of said oil, and a corrosion inhibitor comprising an ester containing an amino sub- 'the' corrosivity of said oil, and a corrosion'inhibitor comprising an ester containing an amino substituent.

4. A liquid compounded hydrocarbon oil con taining a metal salt of a higher aliphatic acid 1 rosion inhibitor comprising an ester containing an amino substituent.

'6. A compounded hydrocarbon oil containing a metal salt of a carboxylic acid having'an aryl substituent. in an amount suflicient substantially to increase the corrosivity of said oil. and a corrosion inhibitor comprising an ester selected from the group consisting of alpha and beta amino substituted esters.

' 7. A compounded hydrocarbon oil containing a metal salt of a high molecular weight phenol in an amount suiiicient substantially to increase the corrosivity of said oil, and a corrosion inhibitor comprising an ester containing an amino substituent.

8. A compounded hydrocarbon oil containing a metal salt of a high molecular weight phenol in an amount suiilcient substantially to increase the corrosivity of said oil, and a corrosion inhibitor comprising an ester selected from the group conasting of alpha and beta amino substituted es- 9. A liquid compounded hydrocarbon oil containing a small amount of a metal salt of an organic acid in an amount suillcient substantially its: increase: the. corrcsii/ity of; said 5e11,: and: iron approximately 0.1% :to19% of a ma: an: aminozsabstituentr f 1.0; Ailinuid; compounded hydrocarbon 01 con aim ng a email amount er a metai sait 50f an or ganic acid; in {an amountzsumcient substantiaili ester contain pproxima ely 1- 1% to; 10% of an ester sei Omthe; grnup: crinsisting taipjhaandbet a no substitued: aster iubricating ie i e im inta a aab a e aflw icn i a :1 8; i m lr rian nigh co copper-lead alloys, a film of a compounded lubricating oil containing a metal salt of an organic acid in an amount which would normally increase the corrosivity of said oil to said bearing metal, the step of inhibiting the corrosive action of the oil on said bearing by incorporating therein from approximately 0.1% to 10% of an ester selected from the group consisting of alpha and beta amino substituted esters.

15. In a method of lubricating bearing surfaces which comprises maintaining between the bearing surfaces, one of which is;a bearing metal of the type represented by cadmium-silver and copper-lead alloys, a film of a compounded lubricating oil containing a metal salt of a higher to increase the. :corro'sivity oi? said oil; and from i t; which ween normally: in;

crease the corrosivity of said oil to said bearing f; popper-lead alioys,=aifiim o awompoundediub eating oi containing a iipha gzof aipha rand betaiaminn substituted esters.

- V In a method: bf lubrica tiirg :ueann surface 'ich: comprises 2 maintaining betwee he bear nig surfaces; zone; of W21 I 7 ii a compounded :1 an at containing a rnetai saiti o" :a' ca 30 cid h vingl an: arm :substitn ent herei rem ma ch" 3.1% to 19% fOf an ester ont ni amino substituentf I '518E111 a?-m=t;li ofdfn TCeSEWhiCh om iseis m 7 :(tOIkSlSi/in off substituted sters I nai= e g me Q the type 1 copper-lead alloys, a film of a compounded lubricating oil containing a metal salt of a high molecular weight phenol in an amount'which would normally increase the corrosivity-of said oil to said bearing metal, the step of inhibiting the corrosive action of the oil on said bearing by incorporating therein from approximately 0.1% to 10% of an estecontaining an amino substituent.

20. In a method of lubricating bearing surfaces which comprises maintaining between the bearing surfaces, one of which is a bearing metal of the type represented by cadmium-silver and copper-lead alloys, a film of a compounded lubricating oil containing a metal salt of a high molecular weight phenol in an amountwhich would normally increase the corrosivity of said oil to said bearing metal, the step of inhibiting the corrosive action of the oil on said bearing byv incorporating therein from' approximately 0.1% to 10% of an ester selected from the group consisting of alpha and beta amino substituted esters.

21. A liquid compounded lubricant comprising a hydrocarbon oil containing from approximately 0.1% to 5% of a metal salt of an organic acid and from approximately 0.1% to 10% of a cor-.

rosion inhibitor comprising an ester of a. cal-boxylic acid, said ester having an amino substituent near a carbonyl group thereof.

22. A compounded lubricant comprising a hydrocarbon oil containing from approximately 0.1% to 5% of a metal salt of an organic acid and from approximately 0.1% to 10% of a corthe time represented cadmium-silver and;

etai salt of: a higher presented by cadmium-silver and rosion inhibitor comprising an ester of the type formula:

m-cn- -z-m in which R; and R2 are radicals of hydrocarbon structure; Y and Z are selected from the group c sistine of oxygen and sulfur; and X represents an amino group.

23. P compounded lubricant comprising a hydrocarbon oil containing from approximately 0.1% to 5% 01 a metal salt of an organic acid and from approximately 0.1% to 10% of a corrosion inhibitor comprising an ester of the type formula: r

Ri(IJZCH (IIH-Rz x in which R1 and R2 are radicals of hydrocarbon structure; Y and Z are selected from the group consisting of oxygenand sulfur; and X represents an amino group.

2%. A compounded lubricant comprising a hydrocarbon 011 containing from approximately 0.1% to 5% of a metal salt of an organic acid and from approximately 0.1% to 10% of a corrosion inhibitor comprising an ester of the type formula:

in which R1 and'Rz are radicals of hydrocarbon J o. CLAYTON. moon B. FARRINGTON. 

